Improve LZ4CAT with ability to write to destination file

src/samplesrc/lz4cat.pla

@@ -3,24 +3,28 @@ include "inc/args.plh"
 include "inc/fileio.plh"
 include "inc/lz4.plh"
 
+const ERASE_DST = 1
 struc t_header
     word magic[2]
     byte FLG
     byte BD
 end
 word arg
-byte ref
+byte ioflags
+byte inref, outref
+char[64] infile, outfile
+word[2] eof
 
 def lz4ReadBlock(flags)#2
     word size[2], block, data, len
-    
-    len = fileio:read(ref, @size, 4)
+
+    len = fileio:read(inref, @size, 4)
     if len <> 4 or size[0] == 0 or size[1] & $7FFF
         return NULL, 0
     fin
     block = heapalloc(size[0])
     if block
-        len = fileio:read(ref, block, size[0])
+        len = fileio:read(inref, block, size[0])
         if len <> size[0]
             heaprelease(block)
             return NULL, 0
@@ -49,7 +53,7 @@ def lz4ReadBlock(flags)#2
         heaprelease(block + len)
     fin
     if flags & $10 // Block Checksum
-        fileio:read(ref, @size, 4)
+        fileio:read(inref, @size, 4)
     fin
     return data, len
 end
@@ -57,7 +61,7 @@ def lz4ReadFrame#0
     word data, len
     byte header[t_header], opt
 
-    fileio:read(ref, @header, t_header)
+    fileio:read(inref, @header, t_header)
     if header:magic[1] <> $184D or header:magic[0] <> $2204
         puts("Not LZ4 file.\n")
         return
@@ -77,31 +81,69 @@ def lz4ReadFrame#0
     if header.FLG & $01 // Dictionary ID
         opt = opt + 4
     fin
-    fileio:read(ref, heapmark, opt) // Read rest of header and throw away
+    fileio:read(inref, heapmark, opt) // Read rest of header and throw away
     repeat
         data, len = lz4ReadBlock(header.FLG)
         if len
-            while len
-                putc(^data <> $0A ?? ^data :: $0D)
-                data++
-                len--
-            loop
+            if outref
+                fileio:write(outref, data, len)
+            else
+                while len
+                    putc(^data <> $0A ?? ^data :: $0D)
+                    data++
+                    len--
+                loop
+            fin
             heaprelease(data)
         fin
     until not data
     if header.FLG & $04 // Content Checksun
-        fileio:read(ref, heapmark, 4)
+        fileio:read(inref, heapmark, 4)
     fin
 end
+
 arg = argNext(argFirst)
 if ^arg
-    ref = fileio:open(arg)
-    if ref
-        lz4ReadFrame
-        fileio:close(ref)
-    else
-        puts("File not found.\n")
+    while ^(arg + 1) == '-'
+        when toupper(^(arg + 2))
+            is 'E'
+                ioflags = ioflags | ERASE_DST
+                break
+        wend
+        arg = argNext(arg)
+    loop
+    strcpy(@infile, arg)
+    arg = argNext(arg)
+    if ^arg
+        strcpy(@outfile, arg)
+    fin
+    if infile
+        fileio:iobufalloc(2) // Reserve two I/O buffers
+        inref = fileio:open(@infile)
+        if inref
+            if outfile
+                if ioflags & ERASE_DST
+                    fileio:destroy(@outfile)
+                fin
+                outref = fileio:open(@outfile)
+                if outref
+                    eof[0], eof[1] = fileio:geteof(outref)#2
+                    fileio:setmark(outref, eof[0], eof[1])
+                else
+                    if fileio:create(@outfile, 0, 0) == FILE_ERR_OK
+                        outref = fileio:open(@outfile)
+                    else
+                        puts("Error creating:"); puts(@outfile); putln
+                    fin
+                fin
+            fin
+            lz4ReadFrame
+            fileio:close(0)
+            return 0
+        else
+            puts("Error reading:"); puts(@infile); putln
+        fin
     fin
 fin
-
+puts("Usage: lz4cat <lz4 File> [output file]\n")
 done